Tissue joining and sealing utilizing sutures and staples is the keystone in modem surgical procedures. An alternative approach utilizes a laser to expose a glue or solder to thereby join adjacent tissues. In many respects, such laser assisted tissue soldering is superior to conventional suture or staple-based methods. The advantages are speed, reduced infection, acceleration in healing, better cosmetic appearance and ease of use particularly in laparoscopic surgery where water tightness and limited access or small size of the repair are important. Laser assisted tissue welding often requires glues or solders for promoting strong bonds, forming a bridge between two apposed tissue sections. The ideal solder is chemically and mechanically matched to the tissue. As a result the solder is strong but stretches and grows with the tissue because of good modulus match. Chromophores mixed with the solder can assist in confining the deposited energy and reduce the impact of tissue imperfections. These additives, however, may be toxic and cause pernicious effects.
The need to provide reliable sutureless closures is paramount to reducing morbidity and mortality rates and lowering health care costs. Achieving complete anastomotic integrity without damaging native tissues will provide the general surgeon with a very powerful tool. For example, laser assisted tissue welding can be used in heart surgery to repair congenital defects thereby eliminating blood loss, the main cause of mortality in these procedures. Tissue welding can also benefit patients with coagulation abnormalities, those suffering from dissection of the aorta and those undergoing minimally invasive coronary artery by-pass grafting (CABG). Laser assisted anastomoses will prevent post-operative leakage in bowel and esophageal repair. It will provide a means for repairing damage to articular cartilage, a common problem affecting joints of millions of people. Sutureless transplantation of osteochondral autografts can reduce pain and recovery time and eventually eliminate the need for total joint replacement. The use of a solder will further reduce dead spaces between circular grafts and provide a bridge for optimizing the different mechanical properties of donor to recipient hyaline cartilage. Laser assisted tissue welding can also be used to repair meniscal and treat osteoarthritis and spinal disc injuries and are among other applications of this invention.
Methods reported to date have not gained clinical acceptance. The major reasons include the high level of surgeon skill that is required, the strength, toxicity and resorbability of the tissue solder, the potential for irreparable laser damage and cost of the laser system.